import java.util.*;
class Example2_5{
  public static void main (String args[]){
     int start = 0,end ,middle;
     int a[] = {12,45,67,89,123,-45,67};
     int N = a.length;
     for(int i=0;i<N;i++){
     for(int j=i+1;j<N;j++){
       if(a[j] < a[i] ){
         int t = a[j];
         a[j] = a[i];
         a[i] = t;
       }
     }
   }
     Scanner scanner = new Scanner(System.in);
     System.out.println("输入一个整数，程序判断该数是否在数组中：");
     int number = scanner.nextInt();
     int count =0;
     end = N;
     middle=(start+end)/2;
     while(number!=a[middle]){
        if(number>a[middle])
          start = middle;
        else if (number < a[middle])
          end = middle;
        middle = (start+end)/2;
        count++;
        if(count>N/2)
          break;
   }
        if(count>N/2)
          System.out.printf("%d 不在数组中.\n",number);
        else
          System.out.printf("%d 在数组中.\n",number);
   }
}












  
   
